Oka Y, Fujiwara K, Endou H
First Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Pediatr Nephrol. 1988 Jan;2(1):124-8. doi: 10.1007/BF00870392.
The developmental changes in epidermal growth factor (EGF) have been studied in tissue homogenates, kidney slices, and microdissected nephron segments of the mouse. Immunoreactive EGF concentration per milligram of protein increased in the kidney by about 20-fold from 1 week to 3 weeks of life, reaching the highest levels between 5 and 7 weeks, and decreasing by 10 weeks of life. The time course of the changes was different from those of submaxillary and urinary EGF. Above 7 weeks of age, kidney EGF was higher in female than in male mice. Among various zones of the kidney (outer cortex, inner cortex, outer medulla I, II and papilla), the outer medulla I and II contained the highest quantities of EGF per gram of wet tissue. The highest EGF content per millimeter length was observed in the medullary and cortical thick ascending limbs of Henle's loop. The amounts exceeded by about 4.5-fold those found in glomeruli and in proximal convoluted and proximal straight tubules, and by about 3-fold those present in distal and collecting tubules. Unilateral nephrectomy resulted in no significant changes in EGF levels in the contralateral kidney. The results suggest that the ontogeny of kidney EGF is different from that of the EGF found in the submaxillary gland, and that there is nephron heterogeneity in EGF content.
已对小鼠组织匀浆、肾切片及显微解剖的肾单位节段中表皮生长因子（EGF）的发育变化进行了研究。每毫克蛋白质中免疫反应性EGF浓度在小鼠出生后1周龄至3周龄期间，在肾脏中增加了约20倍，在5至7周龄时达到最高水平，至10周龄时下降。其变化的时间进程与颌下腺和尿液中的EGF不同。7周龄以上，雌性小鼠肾脏中的EGF含量高于雄性小鼠。在肾脏的各个区域（外皮质、内皮质、外髓质I、II和乳头）中，每克湿组织中外髓质I和II含有的EGF量最高。在髓袢升支粗段和皮质厚段中，每毫米长度的EGF含量最高。其含量比肾小球、近端曲管和近端直小管中的含量高出约4.5倍，比远端小管和集合管中的含量高出约3倍。单侧肾切除对侧肾脏中EGF水平无显著变化。结果表明，肾脏EGF的个体发生不同于颌下腺中的EGF，并且在EGF含量方面存在肾单位异质性。
